In long term evolution (LTE), a wireless communication scheme referred to as 5G has been studied to achieve larger capacity of systems, further acceleration of data transmission speeds, further reduction of latency in wireless sections, and the like. In 5G, various component technologies have been studied to satisfy the requirement that latency in a wireless section is set to be less than or equal to 1 ms while achieving a throughput that is greater than or equal to 10 Gbps.
In 5G, it is assumed to use a higher frequency band than that of LTE. Here, a propagation loss increases in a high frequency band. Therefore, to compensate for the increase in the propagation loss, it has been studied to apply massive multi input multi output (MIMO) in which beam forming of a narrow beam width is performed. Massive MIMO is large-scale MIMO in which many antenna elements (for example, 100 elements) are installed on a base station side. Since the strength of an electric field can be concentrated on a narrow region, interference between users can be decreased.
FIG. 1A illustrates an example of beam forming performed by a base station of the related art in LTE or the like. FIG. 1B illustrates an example of beam forming performed by a base station using massive MIMO. In the massive MIMO, as illustrated in FIG. 1B, wireless signals can be transmitted to distance locations through beam forming of a narrow beam width.